Grantee Research Project Results

A smartphone-based colorimetric sensor for household lead detection

EPA Grant Number: SU840409
Title: A smartphone-based colorimetric sensor for household lead detection
Investigators: Wei, Haoran , Cho, Seo Won , Butler, Craig , Wang, Hanwei
Institution: University of Wisconsin - Madison
EPA Project Officer: Harper, Jacquelyn
Phase: I
Project Period: July 1, 2022 through June 30, 2023
Project Amount: $25,000
RFA: 18th Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2021) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Description:

Lead poisoning is related to the damage of brain function and nervous system and especially detrimental to the development and growth of children. One of the major sources of lead exposure is the corrosion of lead service lines (LSLs) that are used in aging infrastructures for drinking water distribution. Approximately 80% of the households in Chicago are still receiving drinking water supplied by LSLs. As indicated by the Flint Water Crisis, lead poisoning is usually a case of environmental injustice, in which underserved communities usually have less economic and political power to identify and address these issues. Therefore, there is a strong demand for household sensors that can provide regular monitoring of lead level in drinking water at a minimum cost. The overall goal of the proposed research is to develop a smartphone-based lead sensor for disadvantaged households in South Side, Chicago, and provide lead-related educational sessions for the residents and schools in the community. The innovative technological aspects of this research include: 1) application of the novel gold Janus nanorods (Au JNRs) with improved aggregation control; 2) ligand functionalization of Au JNRs to achieve sensitive and selective lead ion complexation; and 3) application of smartphone apps for color decryption to achieve easy and rapid lead ion quantification. 

Objective:

The proposed project aligns with the P3 approach in that it emphasizes the protection of the environment and public health from lead contamination. The core of this sensor – Au JNRs exhibits high colloidal stability in challenging water matrices due to the extra steric hindrance provided by the partial silica coating. Upon lead exposure, the Au JNRs aggregate into smaller aggregates, making the sensing dynamic range highly controllable and reproducible. Compared with the previously reported lead sensors, the proposed Au JNR-based colorimetric sensor will offer high sensitivity, selectivity, and reliability. Education on lead toxicity, wide deployment of the proposed colorimetric sensor, training on sensor operations, and illumination on the possible expansion of the project to the state and national level will allow South Side residents to actively engage in routine monitoring of lead. Regular inspection of drinking water quality will prevent the intake of lead and promote both physical and mental well-being of the residents. 

Expected Results:

In this proposed research project, we expect to develop a smartphone-based colorimetric sensor for household lead detection. The excellent sensitivity, selectivity, reusability, and cost-efficiency of the proposed sensor will allow affordable and routine monitoring of lead in disadvantaged communities. Technical feasibility will be evaluated by traditional laboratory-based analytical methods, while small-scale sampling will be implemented for on-site testing. Furthermore, the development and distribution of the sensors will further trigger chain reactions: increased social awareness and extensive citizen science for lead monitoring, promotion of government-level lead control, and successive job creation for sensor production and maintenance.  

Contribution to Pollution Prevention or Control: 
The proposed research project will contribute to the routine monitoring of lead level in drinking water among disadvantaged communities of South Side, Chicago. With increased knowledge of lead toxicity and exposure, residents will be empowered to reduce the consumption of contaminated water and urge the implementation of further actions for lead pollution control. Furthermore, the proposed smartphone-based sensor will potentially expand the city- and nation-wide lead monitoring capacity. Combined with citizen science and big data analysis, the test results uploaded from user end to the cloud platform will constitute a large dataset that can be used for drinking water management and scientific research. 

Supplemental Keywords:

Drinking water monitoring, Plasmonic colorimetric sensor, Gold Janus nanoparticles, Lead pollution, Citizen science, Big data 

Progress and Final Reports:

Final Report

P3 Phase II:

A Smartphone-based Colorimetric Lead Sensor for Household Lead Detection